How Menstrual Cups Are Changing People's Periods

Many users report shorter and lighter periods, so why has no one researched the phenomenon?
hand reaching towards a menstrual cup
Photo: Pixabay

For a full week of every month, Melissa would wear a pair of shorts under her normal clothes. Despite changing her pad every two hours, the 26-year-old from Puerto Rico was so used to her period leaking that she relied on the shorts to soak up any potential public embarrassment. “I had to plan my life around my period, because there were just too many things I couldn’t do,” she said. But after switching to a menstrual cup, Melissa’s periods now last five or six days instead of seven to eight. She says they are also lighter.


Introduced in 1937, menstrual cups have historically flown under the radar. Touted as environmentally friendly, the reusable bell-shaped cup made of medical-grade silicone is folded and inserted, before “popping” open inside the vaginal canal to collect menstrual blood. But there may an unintended benefit to cup use. In a June survey of 1,400 menstrual cup users in the Facebook community page Put A Cup In It, 53 percent said they bled for fewer days after switching to cups. Every source contacted for this article – researchers, medical professionals, educators and cup manufacturers – was well aware of the phenomenon. Not a single scientific study has examined it.

Jen, a member of the Facebook group, said her periods became unmanageable after childbirth. The 39-year-old from Texas described having to run to the bathroom for a tampon change every 45 minutes. “After using the cup for exactly one year, my bleeding has gone from six heavy days to only two days of heavy bleeding, one of regular bleeding,” she said in a message.

Kim Rosas co-founded the Put a Cup In It website, a period education platform that helps people choose between menstrual cup brands. She regularly hears the term “lifesaving” to describe cups, and said stories of shorter periods – as well as lighter periods and less cramping – come up so often in her community she expected an even higher margin from the survey she organised on the Facebook page connected to her platform. “Reducing your waste and saving money are proven benefits of switching to cups, but the unstudied health and comfort outcomes are just as important,” she said.


Menstrual cups are growing in popularity, but still lag behind tampons and pads. Image: Pixabay

In the world of medical research and innovation, money rules. As does the patriarchy: compare the innovations in erectile dysfunction in the past century with the innovation in period products – not to mention that many countries, including Sweden, Norway and Greece, still tax period products as luxury goods. In contrast: In New Zealand, where someone with a period is in charge, Prime Minister Jacinda Ardern recently announced free sanitary products for school kids.

Unlike pads, cups come with a steep learning curve and require the user to really (really) get to know their vagina. There’s a reason thousands of users trade advice in groups like Put a Cup In It. But, once mastered, cups can last up to ten years – saving money and waste. So what if moon cups, as they’re sometimes known, have also been quietly changing periods, to little fanfare?

Dr. Annemieke van Eijk is a senior clinical research fellow at the Liverpool School of Tropical Medicine and co-authored a meta-analysis of menstrual cup research in 2019. While she has heard about cup users experiencing shorter periods anecdotally, Van Eijk confirmed there has never been a clinical study. “There is a lack of research,” she said in an email, “probably because it is [about] women and a subject that is preferably not talked about or taboo”.

That “taboo” sits on a spectrum: from men’s reluctance to discuss periods, to the banishment of women in some communities when they’re bleeding. Claire Baker, a London-based period coach who helps people live in better “sync” with their menstrual cycle, described the lack of interest in women’s health research as a huge problem. “Women have been historically so underrepresented in most medical studies,” she said, suggesting the long-held misconception that there’s “no money” to be made in women’s health was preventing research and innovation.


Baker advocates cups not just for the environmental and financial benefits, but also because, unlike tampons, they don’t contain chemicals or irritate the cervix. “What I’ve noticed with myself and women I’ve worked with is the perception of the amount of blood they’re losing is less,” she speculated about the reports of shorter periods. “Whereas when you're using a pad or tampon, it’s hard to gauge the volume.”

Dr. Jen Gunter, OB/GYN and author of The Vagina Bible, agreed that shortened periods would more likely be the result of people’s perception of the amount of blood. “Women may be noticing blood volumes in a different way with a cup versus a pad or tampon,” she said, while sceptical of any biological difference a cup could make. Fellow OB/GYN and fertility expert, Dr. Larisa Corda suggested the "negative pressure" from the cup's suction may increase the flow of menstrual blood and in turn, "reduce the length of menstruation". She also suggested the chemicals (odour neutralisers, dyes, pesticides and fragrances) used in tampons and pads could potentially affect blood flow and clotting.

“We’ve heard about people having shorter periods and I’ve also personally experienced it,” said Heli Kurjanen, CEO of Finnish menstrual cup manufacturer, Lune. “The feedback is that [periods] are shorter, much lighter than expected and overall people think they are a bit easier to handle when they’re using cups.” Kurjanen emphasised that, while the feedback is promising, it’s ultimately unscientific, and in the form of Facebook messages and emails from customers.

Unsurprisingly, Kurjanen welcomes a proper clinical study. “It’s a shame that it doesn’t seem to be an interesting enough topic for people,” she said. Madalena Limão of Danish cup manufacturer OrganiCup agreed research could be a “game changer” for the industry and anyone with a period. “If these claims were scientifically backed up, it would make a big difference in the lives of people who really struggle with period pain.”

The pandemic has been a stark and often painful reminder that little matters more than health. Sandra, from South Carolina in the US, started using cups just five months ago at the age of 40. “I noticed less cramping immediately, and that my bleeding lasts about a day less,” she said in a message. “I also feel like I'm not bleeding as heavily as I used to. I wish I'd bought one years ago.”

It’s hard to imagine such a potential for change going unnoticed if it involved men’s bodies. If you get your period, or care about someone who does, that should piss you off.